It's been a choppy week on Wall Street. Going into Friday, the Dow is down 2 points, the S&P 500 is up 0.6% and the Nasdaq is 0.9% higher.

Overall, the major indexes are on a roll, up the past two weeks. The Dow and S&P 500 are around their highest levels since the summer of 2008, while the Nasdaq is near the highest point since December 2000.

In Europe, efforts continue to bring the continent's debt crisis under control.

At the end of a two-day meeting in Brussels, 25 of the 27 leaders in the European Union signed a so-called fiscal compact, designed to prevent a future crisis by strengthening budget discipline. As expected, the Czech Republic did not sign due to political obstacles, and U.K. Prime Minster David Cameron also sat out.

The pact still needs to be approved by the parliaments of individual governments. It will be legally binding after it has been ratified by 12 member states and incorporated into EU treaties within five years, the leaders said.

There has been some good news out of Europe recently, as Greece appears to have secured a second bailout, and the European Central Bank has completed a second round of loans to European banks worth €529.5 billion.

Concerns remain, however, about Greece's stability and Europe's capacity to support larger economies like Italy and Spain should they face further distress.

European leaders, who are meeting in Brussels, are also under pressure to increase the size of the €500 billion European Stability Mechanism, in order to prevent the spread of financial contagion to these and other countries.

Beyond Europe, investors will continue their close watch on the global oil market and rising gas prices. Gas prices climbed for the 24th straight day Friday, hovering around $3.74 a gallon.

Companies: Shares of Yelp (YELP) will begin trading on the New York Stock Exchange Friday. The reviews sitepriced its initial public offering at $15 a share late Thursday, above the target set by the company. San Francisco-based Yelp said it was selling 7.1 million shares in the offering, raising about $106.5 million in the IPO.

Zynga (ZNGA) shares moved higher after the online game developer announced a new online platform, Zynga.com, which will allow users to play Zynga's games like FarmVille and Words With Friends on its site and reduce the company's dependence on Facebook.